1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2009 SUSE Linux Products GmbH. All rights reserved.
4  *
5  * Authors:
6  *     Alexander Graf <agraf@suse.de>
7  *     Kevin Wolf <mail@kevin-wolf.de>
8  */
9 
10 #include <linux/kvm_host.h>
11 
12 #include <asm/kvm_ppc.h>
13 #include <asm/kvm_book3s.h>
14 #include <asm/book3s/64/mmu-hash.h>
15 #include <asm/machdep.h>
16 #include <asm/mmu_context.h>
17 #include <asm/hw_irq.h>
18 #include "trace_pr.h"
19 #include "book3s.h"
20 
21 #define PTE_SIZE 12
22 
23 void kvmppc_mmu_invalidate_pte(struct kvm_vcpu *vcpu, struct hpte_cache *pte)
24 {
25 	mmu_hash_ops.hpte_invalidate(pte->slot, pte->host_vpn,
26 				     pte->pagesize, pte->pagesize,
27 				     MMU_SEGSIZE_256M, false);
28 }
29 
30 /* We keep 512 gvsid->hvsid entries, mapping the guest ones to the array using
31  * a hash, so we don't waste cycles on looping */
32 static u16 kvmppc_sid_hash(struct kvm_vcpu *vcpu, u64 gvsid)
33 {
34 	return (u16)(((gvsid >> (SID_MAP_BITS * 7)) & SID_MAP_MASK) ^
35 		     ((gvsid >> (SID_MAP_BITS * 6)) & SID_MAP_MASK) ^
36 		     ((gvsid >> (SID_MAP_BITS * 5)) & SID_MAP_MASK) ^
37 		     ((gvsid >> (SID_MAP_BITS * 4)) & SID_MAP_MASK) ^
38 		     ((gvsid >> (SID_MAP_BITS * 3)) & SID_MAP_MASK) ^
39 		     ((gvsid >> (SID_MAP_BITS * 2)) & SID_MAP_MASK) ^
40 		     ((gvsid >> (SID_MAP_BITS * 1)) & SID_MAP_MASK) ^
41 		     ((gvsid >> (SID_MAP_BITS * 0)) & SID_MAP_MASK));
42 }
43 
44 
45 static struct kvmppc_sid_map *find_sid_vsid(struct kvm_vcpu *vcpu, u64 gvsid)
46 {
47 	struct kvmppc_sid_map *map;
48 	u16 sid_map_mask;
49 
50 	if (kvmppc_get_msr(vcpu) & MSR_PR)
51 		gvsid |= VSID_PR;
52 
53 	sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
54 	map = &to_book3s(vcpu)->sid_map[sid_map_mask];
55 	if (map->valid && (map->guest_vsid == gvsid)) {
56 		trace_kvm_book3s_slb_found(gvsid, map->host_vsid);
57 		return map;
58 	}
59 
60 	map = &to_book3s(vcpu)->sid_map[SID_MAP_MASK - sid_map_mask];
61 	if (map->valid && (map->guest_vsid == gvsid)) {
62 		trace_kvm_book3s_slb_found(gvsid, map->host_vsid);
63 		return map;
64 	}
65 
66 	trace_kvm_book3s_slb_fail(sid_map_mask, gvsid);
67 	return NULL;
68 }
69 
70 int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte,
71 			bool iswrite)
72 {
73 	unsigned long vpn;
74 	kvm_pfn_t hpaddr;
75 	ulong hash, hpteg;
76 	u64 vsid;
77 	int ret;
78 	int rflags = 0x192;
79 	int vflags = 0;
80 	int attempt = 0;
81 	struct kvmppc_sid_map *map;
82 	int r = 0;
83 	int hpsize = MMU_PAGE_4K;
84 	bool writable;
85 	unsigned long mmu_seq;
86 	struct kvm *kvm = vcpu->kvm;
87 	struct hpte_cache *cpte;
88 	unsigned long gfn = orig_pte->raddr >> PAGE_SHIFT;
89 	unsigned long pfn;
90 
91 	/* used to check for invalidations in progress */
92 	mmu_seq = kvm->mmu_notifier_seq;
93 	smp_rmb();
94 
95 	/* Get host physical address for gpa */
96 	pfn = kvmppc_gpa_to_pfn(vcpu, orig_pte->raddr, iswrite, &writable);
97 	if (is_error_noslot_pfn(pfn)) {
98 		printk(KERN_INFO "Couldn't get guest page for gpa %lx!\n",
99 		       orig_pte->raddr);
100 		r = -EINVAL;
101 		goto out;
102 	}
103 	hpaddr = pfn << PAGE_SHIFT;
104 
105 	/* and write the mapping ea -> hpa into the pt */
106 	vcpu->arch.mmu.esid_to_vsid(vcpu, orig_pte->eaddr >> SID_SHIFT, &vsid);
107 	map = find_sid_vsid(vcpu, vsid);
108 	if (!map) {
109 		ret = kvmppc_mmu_map_segment(vcpu, orig_pte->eaddr);
110 		WARN_ON(ret < 0);
111 		map = find_sid_vsid(vcpu, vsid);
112 	}
113 	if (!map) {
114 		printk(KERN_ERR "KVM: Segment map for 0x%llx (0x%lx) failed\n",
115 				vsid, orig_pte->eaddr);
116 		WARN_ON(true);
117 		r = -EINVAL;
118 		goto out;
119 	}
120 
121 	vpn = hpt_vpn(orig_pte->eaddr, map->host_vsid, MMU_SEGSIZE_256M);
122 
123 	kvm_set_pfn_accessed(pfn);
124 	if (!orig_pte->may_write || !writable)
125 		rflags |= PP_RXRX;
126 	else {
127 		mark_page_dirty(vcpu->kvm, gfn);
128 		kvm_set_pfn_dirty(pfn);
129 	}
130 
131 	if (!orig_pte->may_execute)
132 		rflags |= HPTE_R_N;
133 	else
134 		kvmppc_mmu_flush_icache(pfn);
135 
136 	rflags = (rflags & ~HPTE_R_WIMG) | orig_pte->wimg;
137 
138 	/*
139 	 * Use 64K pages if possible; otherwise, on 64K page kernels,
140 	 * we need to transfer 4 more bits from guest real to host real addr.
141 	 */
142 	if (vsid & VSID_64K)
143 		hpsize = MMU_PAGE_64K;
144 	else
145 		hpaddr |= orig_pte->raddr & (~0xfffULL & ~PAGE_MASK);
146 
147 	hash = hpt_hash(vpn, mmu_psize_defs[hpsize].shift, MMU_SEGSIZE_256M);
148 
149 	cpte = kvmppc_mmu_hpte_cache_next(vcpu);
150 
151 	spin_lock(&kvm->mmu_lock);
152 	if (!cpte || mmu_notifier_retry(kvm, mmu_seq)) {
153 		r = -EAGAIN;
154 		goto out_unlock;
155 	}
156 
157 map_again:
158 	hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
159 
160 	/* In case we tried normal mapping already, let's nuke old entries */
161 	if (attempt > 1)
162 		if (mmu_hash_ops.hpte_remove(hpteg) < 0) {
163 			r = -1;
164 			goto out_unlock;
165 		}
166 
167 	ret = mmu_hash_ops.hpte_insert(hpteg, vpn, hpaddr, rflags, vflags,
168 				       hpsize, hpsize, MMU_SEGSIZE_256M);
169 
170 	if (ret == -1) {
171 		/* If we couldn't map a primary PTE, try a secondary */
172 		hash = ~hash;
173 		vflags ^= HPTE_V_SECONDARY;
174 		attempt++;
175 		goto map_again;
176 	} else if (ret < 0) {
177 		r = -EIO;
178 		goto out_unlock;
179 	} else {
180 		trace_kvm_book3s_64_mmu_map(rflags, hpteg,
181 					    vpn, hpaddr, orig_pte);
182 
183 		/*
184 		 * The mmu_hash_ops code may give us a secondary entry even
185 		 * though we asked for a primary. Fix up.
186 		 */
187 		if ((ret & _PTEIDX_SECONDARY) && !(vflags & HPTE_V_SECONDARY)) {
188 			hash = ~hash;
189 			hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
190 		}
191 
192 		cpte->slot = hpteg + (ret & 7);
193 		cpte->host_vpn = vpn;
194 		cpte->pte = *orig_pte;
195 		cpte->pfn = pfn;
196 		cpte->pagesize = hpsize;
197 
198 		kvmppc_mmu_hpte_cache_map(vcpu, cpte);
199 		cpte = NULL;
200 	}
201 
202 out_unlock:
203 	spin_unlock(&kvm->mmu_lock);
204 	kvm_release_pfn_clean(pfn);
205 	if (cpte)
206 		kvmppc_mmu_hpte_cache_free(cpte);
207 
208 out:
209 	return r;
210 }
211 
212 void kvmppc_mmu_unmap_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *pte)
213 {
214 	u64 mask = 0xfffffffffULL;
215 	u64 vsid;
216 
217 	vcpu->arch.mmu.esid_to_vsid(vcpu, pte->eaddr >> SID_SHIFT, &vsid);
218 	if (vsid & VSID_64K)
219 		mask = 0xffffffff0ULL;
220 	kvmppc_mmu_pte_vflush(vcpu, pte->vpage, mask);
221 }
222 
223 static struct kvmppc_sid_map *create_sid_map(struct kvm_vcpu *vcpu, u64 gvsid)
224 {
225 	unsigned long vsid_bits = VSID_BITS_65_256M;
226 	struct kvmppc_sid_map *map;
227 	struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
228 	u16 sid_map_mask;
229 	static int backwards_map = 0;
230 
231 	if (kvmppc_get_msr(vcpu) & MSR_PR)
232 		gvsid |= VSID_PR;
233 
234 	/* We might get collisions that trap in preceding order, so let's
235 	   map them differently */
236 
237 	sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
238 	if (backwards_map)
239 		sid_map_mask = SID_MAP_MASK - sid_map_mask;
240 
241 	map = &to_book3s(vcpu)->sid_map[sid_map_mask];
242 
243 	/* Make sure we're taking the other map next time */
244 	backwards_map = !backwards_map;
245 
246 	/* Uh-oh ... out of mappings. Let's flush! */
247 	if (vcpu_book3s->proto_vsid_next == vcpu_book3s->proto_vsid_max) {
248 		vcpu_book3s->proto_vsid_next = vcpu_book3s->proto_vsid_first;
249 		memset(vcpu_book3s->sid_map, 0,
250 		       sizeof(struct kvmppc_sid_map) * SID_MAP_NUM);
251 		kvmppc_mmu_pte_flush(vcpu, 0, 0);
252 		kvmppc_mmu_flush_segments(vcpu);
253 	}
254 
255 	if (mmu_has_feature(MMU_FTR_68_BIT_VA))
256 		vsid_bits = VSID_BITS_256M;
257 
258 	map->host_vsid = vsid_scramble(vcpu_book3s->proto_vsid_next++,
259 				       VSID_MULTIPLIER_256M, vsid_bits);
260 
261 	map->guest_vsid = gvsid;
262 	map->valid = true;
263 
264 	trace_kvm_book3s_slb_map(sid_map_mask, gvsid, map->host_vsid);
265 
266 	return map;
267 }
268 
269 static int kvmppc_mmu_next_segment(struct kvm_vcpu *vcpu, ulong esid)
270 {
271 	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
272 	int i;
273 	int max_slb_size = 64;
274 	int found_inval = -1;
275 	int r;
276 
277 	/* Are we overwriting? */
278 	for (i = 0; i < svcpu->slb_max; i++) {
279 		if (!(svcpu->slb[i].esid & SLB_ESID_V))
280 			found_inval = i;
281 		else if ((svcpu->slb[i].esid & ESID_MASK) == esid) {
282 			r = i;
283 			goto out;
284 		}
285 	}
286 
287 	/* Found a spare entry that was invalidated before */
288 	if (found_inval >= 0) {
289 		r = found_inval;
290 		goto out;
291 	}
292 
293 	/* No spare invalid entry, so create one */
294 
295 	if (mmu_slb_size < 64)
296 		max_slb_size = mmu_slb_size;
297 
298 	/* Overflowing -> purge */
299 	if ((svcpu->slb_max) == max_slb_size)
300 		kvmppc_mmu_flush_segments(vcpu);
301 
302 	r = svcpu->slb_max;
303 	svcpu->slb_max++;
304 
305 out:
306 	svcpu_put(svcpu);
307 	return r;
308 }
309 
310 int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr)
311 {
312 	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
313 	u64 esid = eaddr >> SID_SHIFT;
314 	u64 slb_esid = (eaddr & ESID_MASK) | SLB_ESID_V;
315 	u64 slb_vsid = SLB_VSID_USER;
316 	u64 gvsid;
317 	int slb_index;
318 	struct kvmppc_sid_map *map;
319 	int r = 0;
320 
321 	slb_index = kvmppc_mmu_next_segment(vcpu, eaddr & ESID_MASK);
322 
323 	if (vcpu->arch.mmu.esid_to_vsid(vcpu, esid, &gvsid)) {
324 		/* Invalidate an entry */
325 		svcpu->slb[slb_index].esid = 0;
326 		r = -ENOENT;
327 		goto out;
328 	}
329 
330 	map = find_sid_vsid(vcpu, gvsid);
331 	if (!map)
332 		map = create_sid_map(vcpu, gvsid);
333 
334 	map->guest_esid = esid;
335 
336 	slb_vsid |= (map->host_vsid << 12);
337 	slb_vsid &= ~SLB_VSID_KP;
338 	slb_esid |= slb_index;
339 
340 #ifdef CONFIG_PPC_64K_PAGES
341 	/* Set host segment base page size to 64K if possible */
342 	if (gvsid & VSID_64K)
343 		slb_vsid |= mmu_psize_defs[MMU_PAGE_64K].sllp;
344 #endif
345 
346 	svcpu->slb[slb_index].esid = slb_esid;
347 	svcpu->slb[slb_index].vsid = slb_vsid;
348 
349 	trace_kvm_book3s_slbmte(slb_vsid, slb_esid);
350 
351 out:
352 	svcpu_put(svcpu);
353 	return r;
354 }
355 
356 void kvmppc_mmu_flush_segment(struct kvm_vcpu *vcpu, ulong ea, ulong seg_size)
357 {
358 	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
359 	ulong seg_mask = -seg_size;
360 	int i;
361 
362 	for (i = 0; i < svcpu->slb_max; i++) {
363 		if ((svcpu->slb[i].esid & SLB_ESID_V) &&
364 		    (svcpu->slb[i].esid & seg_mask) == ea) {
365 			/* Invalidate this entry */
366 			svcpu->slb[i].esid = 0;
367 		}
368 	}
369 
370 	svcpu_put(svcpu);
371 }
372 
373 void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
374 {
375 	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
376 	svcpu->slb_max = 0;
377 	svcpu->slb[0].esid = 0;
378 	svcpu_put(svcpu);
379 }
380 
381 void kvmppc_mmu_destroy_pr(struct kvm_vcpu *vcpu)
382 {
383 	kvmppc_mmu_hpte_destroy(vcpu);
384 	__destroy_context(to_book3s(vcpu)->context_id[0]);
385 }
386 
387 int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
388 {
389 	struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
390 	int err;
391 
392 	err = hash__alloc_context_id();
393 	if (err < 0)
394 		return -1;
395 	vcpu3s->context_id[0] = err;
396 
397 	vcpu3s->proto_vsid_max = ((u64)(vcpu3s->context_id[0] + 1)
398 				  << ESID_BITS) - 1;
399 	vcpu3s->proto_vsid_first = (u64)vcpu3s->context_id[0] << ESID_BITS;
400 	vcpu3s->proto_vsid_next = vcpu3s->proto_vsid_first;
401 
402 	kvmppc_mmu_hpte_init(vcpu);
403 
404 	return 0;
405 }
406